Steam generator



April 3, 1934. E. FROEHLICH El AL STEAM GENERATOR Filed March 27, 1931 i ah'ii INVENTORS Emilio men/1271 05ml" flee/(Z BY 2 g; m 2 a a & ATTORNEY Patented Apr. 3, 1934 UNITED STATES PATENT @FFIUE Application March 27, 1931, Serial No. 525,852 In Italy March 25, 1930 5 Claims.

This invention relates to new and useful improvements in a steam generator.

The invention has for an object the provision of a steam generator which is characterized by a burner adapted to use gaseous, liquid or pulverized fuel, a header chamber located to encircle the flame of the burner, a nest of tubes connected with said header chamber and extending into the flame, the top tube of said nest discharging steam into a steam chamber encircling said burner to blow or suck fuel from the burner and produce great heat, and means for maintaining a certain water level in the header chamber and a certain steam pressure therein with the stream Withdrawn at a constant rate substantially as fast as it is formed.

The new burner according to this invention differs essentially from all similar hitherto known apparatuses which consists in serpentine pipes, the invention burners principal feature is an arrangement whereby the nests of tubes are arranged of substantially U-shape, but turned on one side and having their lower arms connected with the water portion of the header chamber and the upper arms connected with the steam portion thereof and said header chamber being connected with a water feed through a float casing in such a way that any variation of the water level which is controlled by a float valve and a check valve operating in series, produces a correspondingly uniform alteration of the evaporative surface in every one of the tubes of said nests.

In the main types of steam generators consistf ing in serpentine-pipes, the steam bubbles therein produced have transversed the whole length of the pipes until they discharge into the atomizing nozzle so that they would assemble therein and would produce very strong oscillations in the intensity of the flame. The new burner according to this invention assures a particularly uniform production of steam which excludes any undesirable fluctuation of the pressure and consequently of the discharge of said steam which would cause great variation in the flames.

Furthermore it is proposed to directly connect the float and check valves, which control the water level in the steam generator with the steam generator itself, without any disturbing interpolations, so that the same working conditions prevail in the whole system, and therefor any rise of steam pressure due to either an increase of the evaporative surface or an increase of the steam production relative to the steam withdrawal owing to the rising of temperature of the (Cl. 122--10) j tubes, causes an immediate closing of the check valve which shuts ofi the feed Water. The water level decreases almost instantly, and. due to the extreme sensitivity of the generator, the evaporative surface of each tube is reduced quickly. The quantity of steam produced in the steam unit is therefore at once reduced accordingly, so that the balance between the pressure is promptly restored.

Furthermore the invention proposes an arrangment to obtain a perfect atomization 0f the fuel by reason of delivering super-heated steam to the steam chamber of the burner. vIt is proposed that this object be attained by arranging said top tube in a manner so that one end is connected with the steam portion of the header chamber and the other end discharges the steam into the burner so that this top tube acts as a super-heater for the steam produced. I

As a still further object of this invention it is proposed to arrange the tubes which form the nest so as to be separated from each other providing ample space for the passage of the flame.

A still further object of this invention is to arrange a second header spaced from the first header and a nest of tubes extending from these headers.

Furthermore as another object it is proposed to form the header chamber of circular form so as to conveniently encircle the flame.

Another one of the objects of this invention is the provision of a check valve and a water level valve in series as constituting the means for maintaining the water in the header at a certain level and the steam at a certain pressure with the steam generator operating so that the steam is withdrawn at a constant rate substantially as fast as it is produced.

Furthermore as another object it is proposed to connect the steam portion of the header above the water level of the water level valve in a manner so that the pressure may act against the check valve and keep the steam pressure at a constant average value with the steam generator operating so that the steam is withdrawn at a constant rate substantially as fast as it is produced.

Furthermore as a still further object of this invention it is proposed to construct a steam generator which is of simple durable construction, dependable in use and efficient in action, and which can be manufactured and sold at a reasonable cost.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawing forming a material part of this disclosure:-

Fig. 1 is a longitudinal vertical sectional view of a steam generator burner constructed according to this invention.

Fig. 2 is a transverse sectional View taken on the line 2-2 of Fig. 1.

Fig. 3 is a rear elevational view of Fig. 1.

Fig. 4 is a view similar to a portion of Fig. 1, but illustrating a modified arrangement.

The steam generator burner according to this invention comprises a burner for using gaseous, liquid, or pulverized fuel. This burner is provided with an adjusting stem 11 extending at the discharge end 12 so as to control the size of the discharge. A fuel chamber 13 is arranged around the stem 12 and is provided with an inlet 14 for connection with some source of fuel. A steam chamber 15 is arranged around the fuel chamberl3 in a manner so that the steam may discharge from the opening of theburn'er and suckand draw along the fuel. In this manner avery 'hot' flame can be produced. A header chamber 16 is located to the rear of the burner andis adapted to encircle the flame. This header chamber is of circular form to accomplish the encircling of the flame. It consists of aflat ring plate 1'7 immediately adjacent a hollow ring plate 18. Tongues 19 from one of the plates engages in grooves in the other plate so as to form a tight-connection between these parts. A flange 20 isarranged upon the plate 1'? 'for the purpose of -attaching the header chamber to a support.

A nest of tubes 21 is connected with the header chamber 16 and is arranged so as to extend into the flame of the burner. This nest as shown on the drawing comprises three groups of tubes. Examining Fig. 3 it should be noticed that there are two side groups, indicated by'reference numerals'22 and 23'respe'etive1y, and atop group 24. All of the tubes forming these various groups are spaced from'each other so as to allow the passage'of the flame. Each of the tubes are sub stantially U-shaped in form so that both ends may "connect with the header chamber.

'It should be noticed that each of the tubes of U-shape are arranged so as tohave their lower ends connected with the water portion (lower portion) of the header chamber and the upper arms with the steam portion (upper'portion) thereof. The bends of each of the U-shaped tubes are arranged substantially on the "same horizontal plane as the water surface within the header chamber controlled by a float valve hereinafter described, so that the evaporative surface of the tubes is sensitively controlled by a fluctuation in the water level in the tubes. If the tubes are filled'with more water, more steam willbe produced since this Water is exposed to the heat of the flame of the burner. If there is less Water in the tubes less steam will be produced.

Furthermore the top group 24 of tubes is arranged so as to deliver su er-heated s'team to the steam chamber of the burner. Indetail. the topgroup of tubes have certain oi their endscon nected with the steam portion of the header chamber and another end thereof directedto discharge the steam into the feed chamber of the burner. Thus the steam which is actually delivered to the burner will be very dry and so insure atomization of the fuel.

In Fig. 4 a modified arrangement of the device has been disclosed, in which a second header chamber 25 is provided. The tubes 26 merely extend between both header chambers. The header chamber 25 is very similar to the chamber 16 in that it is composed of a pair of members connected together so as to form a hollow annulus.

One of the tubes from the top nest of tubes 24 extends through the header chamber at the point 2'7 and connects with the stem chamber 15 of the burner. This allows for a proper supply of steam to the burner.

A means is also provided for maintaining a certain water level within the header chamber and a certain steam pressure with the steam generator operating so that the steam is withdrawn at a constant rate substantially as fast as it is produced. This means is in the form of a float valve 28 connected in series with a check valve 29 so as to allow the passage of feed water into the header chamber or to check such passage.

The float valve 28 comprises a body 30 for holding'water 31 provided with a float 32. This float is provided with an adjustable member 33 capable 'of contacting with the float valve 28 while the float 32 is floating at various heights so that the level of the water may be controlled. Upon the body member 30 there is a cap member 34 which is provided with the opening allowing the passage of the valve head 28. This valve head has a pointed portion at the top capable of normally resting upon the bottom of the member 34. When the float rises the valve head is moved upwards so'as to close the passage through a seat member 35 attached upon the member 3%.

The check valve comprises another casing member 36 having a water inlet 37 and a valve seat38 at the end of the water inlet. A ball valve 29 constitutes the check valve and when there is anincrease in pressure sufficient to lift the ball, this ball will act against the seat 38 and close the passage of feed water. The body mem ber 30 is connected by a tube 39 with the bottom of the header chamber 16 so as to cause the water to maintain the corresponding level within the header chamber. A drain pipe 40 is provided in the event that it is desirable to drain the system. Another tube 41 connects withthe top of the header chamber and with a point in the body 30 which is above the water level and on the dis charge side of the check valve 29.

The operation of the device consists in applying it within a boiler or the like for producing steam. The fuel comes inthrough the inlet 14 and discharges from the burner and is there ignited. The flame heats up the nest of tubes 21 and causes the generation of the steam within the header member. The water level in the header member is controlled by the float valve 28. Steam which is generated passes through the top tube 27 and discharges so as to encircle the fuel chamber 13 of the burner. The steam then discharges through the outlet of the burner and draws along the fuel so as to produce a very hot flame.

Thewater level may be controlled by adjusting the adjustable member 33 so as to cause the float 32 to act against'the valve head 28 at a different level of the water. To control the steam pressure within the device, the check valve 29 is provided. 'When this pressure exceeds the pressure in' the feed line the check valve will close the inlet 37' so as to out off any further supply of feed water. 'Since the supply of water is limited the pressure is accordingly limited provided that the steam generator is operating as it is designed for, with the steam being withdrawn at a constant rate substantially as fast as it is produced.

One main feature of this invention is the par ticular arrangement of the tubes forming the nests of tubes 21. Each of these tubes is sub stantially U-shaped and arranged turned upon one side, and furthermore with the lower end connected with the water portion of the header chamber and the upper end connected with the steam portion thereof. Consequently as the water level in the device changes, the evaporative surface will change correspondingly and very quickly therewith. Bevause of the ability of changing so rapidly the device will be extra sensitive to variations of the water level. The steam delivered from the top tube 24 to the burner will be super-heated and so very desirable for the proper atomization of the fuel of the burner.

Furthermore, the steam delivered to the burner will be of constant pressure due to the direct control of the steam pressure and water level by the float valve and check valve arranged 25 in series and the rate of withdrawal of steam. For example, if the water level increases to an undesirable amount the float 32 will close the float valve 28. This will tend to keep the water at a proper level. Should the steam pressure rise the check valve 29 will be forced closed and so cut off additional feed water. Immediately the water level within the system will fall since the Water is continuously being turned into steam which is withdrawn substantially as fast as it is produced. As the water level falls the evaporacoming within the scope of the invention as de fined in the appended claims.

Having thus described our invention, what we claim as new, and desire to secure by United States Letters Patent is:-

1. In a steam generator adapted for operation in which the steam is withdrawn at a constant rate substantially as fast as it is produced; a header member adapted to encircle the flame of a burner for operating on gaseous, liquid or pulverized fuel and having a steam chamber for steam to aid in atomizing the fuel, means for maintaining the feed water from rising above a certain level within said header chamber, groups of tubes connected with said header member and extend into and around the flame of said burner, and comprising side groups and a top tube, each side group comprising a plurality of substantially U-shaped tubes arranged upon one side and having their ends at different elevations, the lower ends of each of the tubes connecting with the water portion of said header chamber and the upper ends with the steam portion of said header chamber, and said top tube having one end connected with the steam portion of the header chamber and the other end adapted for connection with the steam chamber of said burner to deliver super-heated steam to said burner, and means for stopping the supply of feed water when the steam pressure in the header member reaches a predetermined amount.

2. In a steam generator adapted for operation in which the steam is withdrawn at a constant rate substantially as fast as it is produced; a header member adapted to encircle the flame of a burner for operating on gaseous, liquid or pulverized fuel and having a steam chamber for steam to aid in atomizing the fuel means for maintaining the feed water from rising above a certain level within said header chamber, groups of tubes connected with header member and extending into and around the flame of said burner, and comprising side groups and a top tube, each side group comprising a plurality of substantially U-shaped tubes arranged upon one side and having their ends at different elevations the lower ends of each of the tubes connesting with the water portion of said header chamber and the upper ends with the steam portion of said header chamber, and said top tube having one end connected with the steam portion of the header chamber and the other end adapted for connection with the steam chamber of said burner to deiiver super-heated steam to said burner, and means for stopping the supply of feed water when the steam pressure in the g header member reaches a predetermind amount, said means for maintaining the feed water from rising above a certain level within the header chamber comprising a float valve controlling the supply of feed water, said means for stopping the supply of feed water when the steam pressure 108 in the header member reaches a predetermined amount, comprising a. check valve; and said check valve being connected for operation by the steam pressure within said header chamber and said float valve and check valve being arranged 110 in series.

3. In a steam generator, a header member having a chamber for water and for steam above said water, means for maintaining feed water I to said chamber from rising above a predetermined level, groups of tubes connected with said header member and adapted to extend around the flame of a burner for operation on gaseous, liquid or pulverized fuel and having a steam chamber for steam to add in atomizing the fuel, said groups of tubes comprising side nest sections with substantially U-shaped tubes arranged in the vertical and having the lower arms connected with the water portion of said chamber I and the upper arms with the steam portion thereof, and a super-heater tube having one end con nected with the steam portion of said chamber and the other adapted for connection with the steam chamber of said burner to deliver superheated steam thereto, and means for stopping the supply of feed water when the steam pressure in the header member reaches a predetermined amount.

4. In a steam generator, a header member having a chamber for water and for steam above said water, groups of tubes connected with said header member and adapted to extend around the flame of a burner having a steam chamber for steam to aid in atomizing the fuel thereof, said groups of tubes comprising side nest sections 1&0 of substantially U-shaped tubes arranged in the vertical and having their lower arms connected with the water portion of said chamber and the upper arms with the steam portion thereof, and a super-heater tube having one end connected with the steam portion of said chamber and the other adapted for connection with the steam chamber of said burner to deliver super-heated steam thereto.

5. In a steam generator adapted for operation in which the steam is withdrawn at a constant rate substantially as fast as it is produced, a header member adapted to encircle the flame of a burner for operating; on gaseous, liquid or pulverized fuel and having a steam chamber for steam to aid in atomizing the fuel, means for maintaining the feed water from rising above a certain level within said header chamber, groups of tubes connected with said header memher and extending into and. around the flame of said burner, and; comprising side groups and a top tube, each side group, comprising a plu-v rality of substantially U-shaped tubes arranged uponone side and having their ends at different elevations, the lower ends of each of the tubes connecting with the water portion of said header chamber and the upper ends with the steam portion of said header chamber, and said top tube having one end connected with the steam portion of the header chamber and the other end adapted for connection with the steam chamber of said burner to deliver super-heated steam to said burner, and means for stopping the supply of feed water when the steam pressure in the header member reaches a. predetermined amount, said certain Water level. being substantially at the centers of the bends of said U-shaped tubes.

ERVINO FROEHLICH. OSCAR HECKL. 

